The text included advice on tactics with supporting data that included original metrics Old devised such as "shot potency", which worked by ranking a shot"s effectiveness in winning a point.

Attributing a basic potency of 1.0 to a second serve, Old"s data valued a first serve as 1.2 times

อ่านได้ที่>>โรงเรียนวัดหนองกระทุ่ม

นานาสาระ>>เอนไซม์